Windows Live Writer crashes on start when My Documents folder is not accessible

Today I couldn’t start my Windows Live Writer as it had been constantly crashing on start. I had the 2010 version and the error exception on start was the infamous NullReferenceException. I upgraded to the latest Writer 2011 but no lack – this time it kept crashing with Windows Live own exception DirectoryException (obviously the team in the 2011 version did some more checks and create a special exception). But why?

It choked in the WindowsLive.Writer.CoreServices.ApplicationEnvironment method. A little dig in the WindowsLive.Writer.CoreServices.dll in the Reflector shows the culprit:

path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
_myWeblogPostsFolder = _userSettingsRoot.GetString("PostsDirectory", null);
if (string.IsNullOrEmpty(_myWeblogPostsFolder))
{
  if ((_productName == "Windows Live Writer") && string.IsNullOrEmpty(path))
  {
    throw new DirectoryException(MessageId.PersonalDirectoryFail);
  }
  _myWeblogPostsFolder = Path.Combine(path, "My Weblog Posts");
}

Indeed, the Environment.GetFolderPath(Environment.SpecialFolder.Personal) gave null result since I don’t have a custom path for saving blog posts set in the Windows Live Writer.

Then I remembered that we have the My Documents folder redirected on the network share which was unavailable and I had turned off the offline files Windows feature (because it slows down the boot time considerably – to 15 minutes and more).

So either connected to the network to have your My Documents folder accessible or make it available offline when using Windows Live Writer.